<?php
class static_aes
{
    protected $cipher = MCRYPT_RIJNDAEL_128;
    protected $mode = MCRYPT_MODE_ECB;
    protected $pad_method = NULL;
    protected $secret_key = '';
    protected $iv = '';

    public function set_cipher($cipher) {
        $this -> cipher = $cipher;
    }

    public function set_mode($mode) {
        $this -> mode = $mode;
    }

    public function set_iv($iv) {
        $this -> iv = $iv;
    }

    public function set_key($key) {
        $this -> secret_key = $key;
    }

    public function require_pkcs5() {
        $this -> pad_method = 'pkcs5';
    }

    protected function pad_or_unpad($str, $ext) {
        if (is_null($this -> pad_method)) {
            return $str;
        } else {
            $func_name = __CLASS__ . '::' . $this -> pad_method . '_' . $ext . 'pad';
            if (is_callable($func_name)) {
                $size = mcrypt_get_block_size($this -> cipher, $this -> mode);
                return call_user_func($func_name, $str, $size);
            }
        }
        return $str;
    }

    protected function pad($str) {
        return $this -> pad_or_unpad($str, '');
    }

    protected function unpad($str) {
        return $this -> pad_or_unpad($str, 'un');
    }

    public function encrypt($str) {
        $str = $this -> pad($str);
        $td = mcrypt_module_open($this -> cipher, '', $this -> mode, '');

        if (empty($this -> iv)) {
            $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        } else {
            $iv = $this -> iv;
        }

        mcrypt_generic_init($td, $this -> secret_key, $iv);
        $cyper_text = mcrypt_generic($td, $str);
        $rt = base64_encode($cyper_text);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        return $rt;
    }

    public function decrypt($str) {
        $td = mcrypt_module_open($this -> cipher, '', $this -> mode, '');

        if (empty($this -> iv)) {
            $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        } else {
            $iv = $this -> iv;
        }
        mcrypt_generic_init($td, $this -> secret_key, $iv);
        $decrypted_text = mdecrypt_generic($td, base64_decode($str));
        $rt = $decrypted_text;
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);
        return $this -> unpad($rt);
    }

    public static function hex2bin($hexdata) {
        $bindata = '';
        $length = strlen($hexdata);
        for ($i = 0; $i < $length; $i += 2) {
            $bindata .= chr(hexdec(substr($hexdata, $i, 2)));
        }
        return $bindata;
    }

    public static function pkcs5_pad($text, $blocksize) {
        $pad = $blocksize - (strlen($text) % $blocksize);
        return $text . str_repeat(chr($pad), $pad);
    }

    public static function pkcs5_unpad($text) {
        $pad = ord($text{strlen($text) - 1});
        if ($pad > strlen($text))
            return false;
        if (strspn($text, chr($pad), strlen($text) - $pad) != $pad)
            return false;
        return substr($text, 0, -1 * $pad);
    }

}

/*
$aes = new static_aes();
//密钥修改成了16位 和JAVA的一致
$aes -> set_key('abcd1234abcd1234');
//$aes->set_key('AKlMU89D3FchIkhKyMma6FiE');
$aes -> require_pkcs5();
$rt = $aes -> encrypt('金融科技网店贷款系统-RLMS 测试');
*/
?>